1)Write the equation again, but replace ___ with x:
(2y + 4b) + 5 = x + (4b + 5)
2) Eliminate parenthesizes (if there is "-" in front of them, change the sign in front of everything that is inside them; if there is "+" just leave it the same):
2y + 4b + 5 = x + 4b + 5
3) Transfer 4b + 5 from the left side to the right by changing signs into the opposite ones:
2y = x + 4b + 5 - 4b - 5
2y = x
So, the answer will be 2y. Hope this helps!